Cartography and the Internet:
Implications for Modern Cartography

Michael P. Peterson

University of Nebraska-Omaha
geolib@cwis.unomaha.edu




Abstract

The number of maps that are currently distributed through the Internet is phenomenal. A single World-Wide-Web site operated by the Xerox Palo Alto Research Center in California processes over 90,000 Internet requests for maps every day and the number of web sites that contain maps numbers into the tens of thousands. A major reason for the increase of map distribution through the Internet is cost. It is simply less expensive to distribute color graphics through the web than it is to print and distribute maps on paper. A second reason is time. Maps on computer networks are delivered in a fraction of the time that was previously required. A third reason is the potential for interaction. Users can interactively choose a location to map and the features to include on the map. The implications of the Internet for cartography are examined through a World Wide Web home page at http://maps.unomaha.edu/NACIS/paper.html.


Introduction


No longer restricted to paper, maps are now transmitted almost instantly from place to place. The change in the medium of map distribution has been phenomenal. By the mid-1990's, a single computer operated by Xerox Parc Research Facility in California, processed over 90,000 Internet requests for maps every day. The number of Internet sites that contain maps probably numbers into the tens of thousands. Many of these maps, such as those depicting weather patterns, are updated continuously throughout the day.

This document and associated material on the World Wide Web (or simply, the "web") serves as an introduction to this new era in cartography. The text introduces the basic concepts. Resources on the web, linked directly from this document, illustrate and expand upon these concepts. The material is dependent on each other and the reader is encouraged to examine the various links that are implemented within this document. We begin first with an overview of the Internet and the World Wide Web.

I. The Internet

The Internet has been described in many ways. In the simplest sense, the Internet may be thought of as a system for transferring files between computers. These files, manipulated as numbers and ultimately stored and transferred in binary 0s and 1s, may consist of text, pictures, graphics, sound, animations, movies, or even computer programs. Defined in terms of hardware, the Internet may be thought of as a physical collection of computers, routers, and high-speed communication lines. In terms of software, it is a network of computer networks that are based on the TCP/IP protocol. In terms of content, the Internet is a collection of shared resources. Finally, and most importantly, from a human standpoint, the Internet is a large and ever-expanding community of people who contribute to its content and who use its resources.

The beginnings of the Internet can be found in ARPAnet - a computer network created for the Advanced Research Projects Agency and funded by the U.S. Department of Defense. The inital purpose of the network was to help scientists work together and also to create a network with a redundantly linked structure that would continue to work even after a limited nuclear attack. The initial Network Control Protocol (NCP) was first implemented in 1969 between Stanford University, UC-Santa Barbara, and the University of Utah. ARPANET switched from the NCP protocol to the currently used TCP/IP (Transmission Control Protocol/ Internet Protocol) on January 1, 1983. Many view this date as the beginning of the Internet.

The ARPAnet model specified that data communication always occurs between a source and a destination computer. Further, the network connecting any two computers is assumed to be unreliable and could disappear at any moment. Sending data from computer to computer required that it be put in an "envelope," called an Internet Protocol (IP) packet, with an appropriate "address." The computers - not the network - had the responsibility for routing the messages. All computers could communicate as a peer with any other computer. If a certain connection between two computers was inoperative, the computer would re-route the message to another computer that would attempt to "deliver" the message.

The ARPAnet model was attractive to governments and universities that didn't have policies concerning the buying of computers from particular vendors. The model of data communications specified by ARPAnet was emulated on a local level to connect often different computers within an organization, particularly when desktop workstations became widely available by the mid-1980s. Workstations, in particular, created a new model of networking. Rather than connecting to a single large timesharing computer per site, users wanted to connect their entire local networks to ARPAnet.

The model was also used in the late 1980s by NSFNET, commissioned by the National Science Foundation (NSF), an agency of the U.S. government. NSFNET was designed to distribute the computing power of five supercomputers at major universities so that they could be used for scholarly research. Increasing demand on the network throughout the 1980's forced the U.S. government to commission the NSF to oversee the network. More research and educational institutions were connected on a high-speed Internet "backbone." Eventually, Internet service providers expanded the network to include telephone access from homes.

The Internet has become an international computer network that links academic, military, government, and commercial computers. It is not managed by any one entity. Rather, it is a system of networks based on the TCP/IP protocol that are linked together in a cooporative, non-centralized collaboration. The Internet consists of five main components or protocols: 1) File Transfer Protocol (FTP) for exchanging files between computers; 2) Telnet - a remote log-on procedure for accessing programs on remote computers as though they were local; 3) e-mail - an electronic mail system whereby one can exchange mail messages between Internet users and many networks outside the The beginnings of the Internet can be found in ARPAnet - a computer network created for the Advanced Research Projects Agency and funded by the U.S. Department of Defense. The inital purpose of the network was to help scientists work together and also to create a network with a redundantly linked structure that would continue to work even after a limited nuclear attack. The initial Network Control Protocol (NCP) was first implemented in 1969 between Stanford University, UC-Santa Barbara, and the University of Utah. ARPANET switched from the NCP protocol to the currently used TCP/IP (Transmission Control Protocol/ Internet Protocol) on January 1, 1983. Many view this date as the beginning of the Internet.

The ARPAnet model specified that data communication always occurs between a source and a destination computer. Further, the network connecting any two computers is assumed to be unreliable and could disappear at any moment. Sending data from computer to computer required that it be put in an "envelope," called an Internet Protocol (IP) packet, with an appropriate "address." The computers - not the network - had the responsibility for routing the messages. All computers could communicate as a peer with any other computer. If a certain connection between two computers was inoperative, the computer would re-route the message to another computer that would attempt to "deliver" the message.

The ARPAnet model was attractive to governments and universities that didn't have policies concerning the buying of computers from particular vendors. The model of data communications specified by ARPAnet was emulated on a local level to connect often different computers within an organization, particularly when desktop workstations became widely available by the mid-1980s. Workstations, in particular, created a new model of networking. Rather than connecting to a single large timesharing computer per site, users wanted to connect their entire local networks to ARPAnet.

The model was also used in the late 1980s by NSFNET, commissioned by the National Science Foundation (NSF), an agency of the U.S. government. NSFNET was designed to distribute the computing power of five supercomputers at major universities so that they could be used for scholarly research. Increasing demand on the network throughout the 1980's forced the U.S. government to commission the NSF to oversee the network. More research and educational institutions were connected on a high-speed Internet "backbone." Eventually, Internet service providers expanded the network to include telephone access from homes.

The Internet has become an international computer network that links academic, military, government, and commercial computers. It is not managed by any one entity. Rather, it is a system of networks based on the TCP/IP protocol that are linked together in a cooporative, non-centralized collaboration. The Internet consists of five main components or protocols: 1) File Transfer Protocol (FTP) - for exchanging files between computers; 2) Telnet - a remote log-on procedure for accessing programs on remote computers as though they were local; 3) e-mail - an electronic mail system whereby one can exchange mail messages between Internet users and many networks outside the Internet (e.g., BITNET); 4) Newsgroups - discussion groups which distribute information to groups of users providing a forum for researchers; and 5) the World Wide Web - a graphical distributed hypermedia system that incorporates most aspects of the previous four services and delivers files in multiple forms, including text, pictures, sound, and animation.

The text-based file transfer systems, including FTP, Telnet, e-mail, and newsgroups developed quickly throughout the 1980's. FTP servers became fairly widespread by the end of the decade but as the number of available files kept increasing, searching for a particular file became unmanageable. Searching systems, including Archie and Gopher, were established to help find particular files. The complexity of using these systems limited their general usefulness. The predominance of text files and the difficulty of transferring and viewing graphic files made the system less than appealing to most computer users.

The World Wide Web

The introduction of the World Wide Web in the early 1990's addressed many of the usability problems associated with computer networks. Files could now be accessed using a pointing device such as a mouse. A link within a document could access another document, on that computer or any other that supported this protocol. The selection of a link automatically made a connection to the remote computer and downloaded the document which could be a text, graphic, sound, animation, or any other type of file. Based on the concepts of hypertext and hypermedia, the web promoted a logical linking of files, much as the human brain links related pieces of information. The World Wide Web is a milestone in network computing technology because it has made it possible for a person with little computing background to make use of the Internet. It is largely responsible for the dramatic growth of the Internet during the early part of the 1990's.

The World Wide Web was conceived at the European Particle Physics Laboratory (CERN) located near Geneva, Switzerland in 1989. Tim Berners-Lee played a large role in designing the system. It was intended to assist researchers in high energy physics research by linking related documents. The developers wanted to create a seamless network in which information from any source could be accessed in a simple and consistent way. Before the WWW, accessing the needed information required the use of many different computer programs largely due to the incompatibility between different sorts of computers. The WWW introduced the principle of "universal readership," which states that networked information should be accessible from any type of computer in any country with a single program. A prototype of the new protocol was finished in 1991 and was largely accepted by 1994. The system was quickly embraced because it also incorporated the previous protocols for file exchange, including FTP, newsgroups, and mail.

The popularity of the WWW can be measured by the quick adoption of the Mosaic WWW browser. Developed and freely distributed by the National Center for Supercomputer Applications (NCSA) in Urbana, Illinois, Mosaic became an instant success. Released for all common computer platforms, including UNIX, PC/Windows, and Macintosh, in September of 1993, it was widely used in a matter of months. Implementing the hypermedia file-access structure, the program incorporated hypertext and hyperimages, to create links to other documents, either text or graphic
The growth of the web during this period was particularly dramatic. The graph in Figure 1.1 illustrates the early increase in WWW packets and bytes relative to other network traffic such as FTP and Gopher. Much of the increase in WWW traffic can be attributed to Internet access by Internet access providers and commercial ventures such as America Online.

World Wide Web Browsers

Mosaic from NCSA was the first, widely-accepted, multimedia-based web browser. Many other web browsers have since become available. Some browsers, such as Lynx, only display text. This book is dependent on the working knowledge of a browser that displays text, graphics, and animation files and plays sound.

One of the more popular browsers is Netscape Navigator. Its main programmer, Marc Andreessen, wrote Mosaic and left NCSA to help form Netscape Communications, Inc. The company experienced phenomenal initial investment in the mid-1990s based on speculation of continued growth of the Internet, particularly the web. A variety of other browsers are also available. Updated versions of Mosaic can still be obtained at no cost from NCSA. Microsoft provides the Explorer browser along with its Windows operating systems. Updates to the popular browsers are available through the web and new functions are being added to the software on a continual basis.
All browsers download and display material from an "http" site (HyperText Transfer Protocol). The "http" address has a consistent structure, as indicated below:
http://maps.unomaha.edu
The "http" prefix is always followed by a colon and two slashes. Following this is the actual address beginning with the name that has been assigned to a particular computer, in this case, "maps". After this is the "domain" name that indicates where that computer is located (the University of Nebraska at Omaha, or "unomaha"). Finally, the "edu" tells us that the computer is at an educational site.
This particular address will display a "home page" for that computer. By adding directory and file name information, one can access other files on the system:
http://maps.unomaha.edu/book2/chapter_1.html
In this case, a file called chapter_1.html within a directory (or folder) called book2 is displayed. This file contains hypertext links that access other sites on the web. This particular file is the web page associated with this chapter.

Browsers also have the option of saving addresses for a particular site as a "bookmark" so that you do not need to type the address each time you want to access a file. This is usually implemented as a menu option and new addresses are added to the menu. The current document is usually displayed in a "Location:" bar at the top of the window. It is important to become accustomed to the use of a particular web browser, including such tasks as typing in the location and saving the location as a bookmark. Other aspects of the browser program can usually be learned by examining a help facility built into the program.

Web Search Engines

A search engine is a method of indexing and finding material on the web. It consists of two basic programs. The first program examines all known web pages and creates an index based on a defined set of keywords. The second program responds to user "keyword" requests to this index. A particular keyword may return a large number of matches. The list of matches are sorted based on a variety of criteria but is usually a function of how often the particular keyword is included in the document.
Search engines work continuously. One of the most powerful search engines on the web is AltaVista, operated by the Digital Equipment Corporation. Its search engine indexes material - "crawls the web" - at 3 million pages a day. AltaVista went public in December of 1995. At the time it had indexed 16 million web pages. Five months later the index had grown to more than 30 million pages and the site was receiving twelve million daily keyword requests. The purpose of the search engine is both find new material and to update HTTP addresses to the pages that have already been indexed.
There are many different search engines (see the list in the home page associated with this chapter). Depending on the search engine, a keyword will return a large number of documents. For example, the keyword "maps" returns 1,127,414 matches in AltaVista (mid-1996). This means that the search engine found this many documents that contained the word "maps". The combination of "maps+world" returns only 1000. There are many ways of limiting the search to a more specific topic but the syntax for doing so varies between different search engines. Effectively "surfing the web" requires a good working knowledge of several search engines.
  1. How To Use Web Search Engines
    Search Engines (try several with an identical keyword):

II. Maps on the Web

Graphics, including maps and images taken from satellites, have become a major component of the web. One of the reasons for this is cost. It is simply less expensive to place color graphics on the web than it is to print in color on paper. When the additional costs of shipping and distribution are factored into the printed product, the cost advantages of distributing maps and images over the Internet become even more apparent.

The advantage of printing, however, is resolution. A typical high-resolution printer has a resolution of between 1200-3400 dots per inch (dpi; 472 - 1339 dots per cm). In contrast, a computer monitor can only display about 65-120 dpi (25.6 - 47.2 dots per cm). The computer monitor is also limited in size, typically only 14" to 21" (35.6 cm - 53.3 cm) in diagonal measure. Printed maps and photographs can be much larger.

We can look at resolution in different ways. The particular type of resolution that is being referred to here is "spatial" resolution - the amount of information or data that can be represented per unit area. Resolution could also refer to other aspects of the display. We might speak of a "temporal resolution" that would describe how quickly a graphic can be displayed. We could also think of resolution in the sense of interactivity - how easily a user can interact with the graphic to change a particular view.

To overcome the limitation of "spatial resolution," maps displayed by computer are typically more dynamic. The maps are frequently updated, they incorporate some type of interaction, or a series of maps can be viewed as an animation. The combination of maps and the Internet is a significant development, not only for improving the distribution of maps but also because it makes a more interactive form of mapping possible - a form of mapping that engages the map user to a much greater extent than maps on paper.

The distribution of maps over the Internet is not new. Map files have been distributed for many years using the FTP protocol. However, these files needed to be subsequently converted and uncompressed before they could be displayed. One also needed the appropriate display software. It was a time-consuming and complex process usually performed on UNIX workstations. WWW browsers incorporated the conversion and display software, either internally or with the help of external "viewer" applications. This made the display of maps possible with a point-and-click interface.

Graphics on the Internet are usually based on a raster format in which the image is represented as a grid of "picture elements" called pixels. Each grid square is assigned a color that is represented in the computer as a number. The most common grid format for graphic files is GIF (Graphics Interchange Format). Limited to 256 shades or colors, GIF files have become a standard way of distributing pictures in electronic form. This graphics format is widely adopted and supported by almost all web browsers. An alternative image display format is JPEG (Joint Photographic Experts Group). This format is better suited for pictures because it is not limited to 256 shades or colors. However, the format makes use of compression algorithms that result in a loss of detail. Although not noticable on pictures, this loss of sharpness is apparent on maps through a fuzziness introduced in the line-work.

Many of the static maps available on the Internet have been scanned from paper maps and stored in a GIF or JPEG format. Examples are this map of Africa and this map of Burma. While the scanning of maps represents a quick way to transform a map into digital form for transmission, the maps are often not legible. Sometimes, so little care is taken in the scanning process that the text on the back side of the paper map will be appear in the scanned version. The screen pattern will be visible on printed maps, particularly those printed in color.

Other forms of static maps include weather maps, maps of demographic distributions (World Per Capita GNP, United States Per Capita GNP) , and other types of thematic maps. Most of these maps have been designed specifically for display on a computer terminal and are much more legible than maps that have been simply scanned. Weather maps, in particular, account for a great deal of network traffic, and incorporate map design considerations for display on a computer terminal.

Static maps with a higher spatial resolution are also available on the Web. A common file type that is used for these maps is Adobe's Portable Document Format (PDF). These files are stored in a format called Postscript that is used by most printers. Although viewable on the screen of the computer, the files are designed for printing. PDF files are "resolution independent" so they can take advantage of the resolution of the printer. An example of a map in PDF format.

A variety of web sites incorporate interactive maps. These maps can be changed by the user by choosing various map display options. Map sites such as those located at Xerox Parc and the Fourmi Laboratory in Switzerland are early examples of the type of interaction that was implemented with maps on the web. Both sites receive a considerable amount of traffic. The interactive Parc site allows the display of alternative projections and separate map layers including country boundaries, waterways, and transportation networks. The map site at the Fourmi Laboratory displays views of the earth from the sun, the moon or orbiting satellites, and includes the overlay of current cloud patterns derived from weather satellites. The XEROX Parc site is one of the most heavily used map sites. By the mid-1990's it was responding to nearly 90,000 requests for world maps. Present Xerox Parc map site usage.

Maps that are updated on a frequent basis include maps of traffic flow, as in this example of the current traffic in Houston . Interactive street level mapping of the US is available from both MapQuest and MapBlast. These maps are based on the TIGER map file, a product of the U.S. Census Bureau. The lcoation of bank teller machines on these maps can be obtained through VISA. Interactive mapping with demographic data is available through CIESIN. This site lets the user choose an area and a data value to map within the U.S. An index of maps on the Internet lists many more sites that distribute maps.

Animated maps are also available through computer networks. Map animations are usually stored in a format designed for the display of movies, such as QuickTime or MPEG. The most common examples of animated maps on the Internet are those of weather patterns, most often depicting the movement of clouds as seen on television weather forecasts. The movement of cloud patterns associated with hurricanes is especially suited for viewing as an animation. Other types of animated maps include terrain fly-throughs in which a landscape, usually somewhat mountainous, is viewed as if it were being flown through with an airplane or jet. Animations are also available showing population growth in a region. Here a shading is applied in a progressive fashion to depict the pattern of population growth. Finally, animations are available that depict temporal trends of alternative methods of data classification. A list of animated maps available through the web is available below:


The Printing Analogy

The first known map dates to about 4500 years ago. However, it wasn't until 500 years ago that humans discovered a way to accurately and quickly duplicate maps. As late as the 1400's, all maps were still painstakingly reproduced by hand, so there were very few maps in existence. Beginning in the latter part of the Renaissance, maps began to be printed in Europe. The development of printing meant that maps could be easily reproduced while being faithful to the original. It also meant that more people had the opportunity to see and use maps.

The impact of printing on mapping has a good analogy in the present transition to the distribution of maps through computer networks. Like the printing of maps, computer networks have increased the distribution of maps. Printing made it possible to produce thousands of identical maps in a short amount of time. The Internet has made it possible to simultaneously "print" and distribute thousands of maps every second.

Maps on computer networks are delivered in a fraction of the time required to distribute maps on paper. A single network request for a map supercedes the former time-consuming map printing and distribution processes. A process that is analogous to the printing and shipping of maps is done on the Internet in a matter of seconds. Like printing, the Internet represents a revolution for mapping in the sense that it redefines how maps are made and used. As you have seen, maps on the Internet tend to be interactive - often allowing the user to change the perspective, the projection, or the level of detail. They tend also to be more up-to-date. Weather maps, for example, are posted on a hourly basis. Finally, maps are used differently than before. They are accessed through a hyperlinking structure that makes it possible to engage the map user on a higher-level than what is possible with a map on paper.

The Map Use Problem

One of the major problems associated with maps is that of map use. Many people have difficulty using maps even within highly educated populations. It has been estimated that more than half of the educated population do not have a basic competency with maps. Most people are essentially map illiterate. The reasons for this are not well understood. Some see the problem related to a lack of education specific to map use while others say it is the maps themselves and, more specifically, the medium of paper that is used to display them. But, the result is clear: people have poorly formed mental representations of their local environment and especially the space beyond their direct experience.

The paper medium has been the predominant form of map distribution. However, the medium does not promote interactivity, a process that many associate with learning. While some people are able to "make a connection" with the map on paper and mentally visualize what the map represents, others have difficulty doing so. Education may help overcome this barrier for some but it is unlikely that it will make the map on paper a viable form of communication for a major segment of the population.

One solution to the problem of map use is the interactivity of maps on the Internet. No longer restricted to the single view offered by maps on paper, the map user is encouraged to explore alternative methods of representation - different views that help shape the user's perspective of the world. The "views" that are presented to people go beyond those offered by the maps in atlases, either those in paper or electronic forms. The maps are more current and targeted to specific users. They can also be more interactive and incorporate animation. The exposure to interactive maps on the Internet may also lead to better map use skills and both improve and increase the use of maps on paper.

The Meaning of Maps on the Web

What is the meaning of this change in how maps are delivered to the map user? Maps are an important source of information from which people form their impressions about places and distributions. Each map is a view of the earth that affects the way people think about the world. Our thoughts about the space in which we live and especially the areas beyond our direct perception are largely influenced by the representations of space that we see, and the way we think about our environment influences the way we act within it. The Internet has already improved the distribution of maps. If done properly, the Internet also has the potential of improving the quality of maps as a form of communication, thereby changing both the mental representations that people have of the world and how people mentally process ideas about spatial relationships.

The Cost of Map Use

Putting maps in "front of people" is the most important aspect of map use. The cost of maps are their production and distribution. As noted earlier in the chapter, the Internet reduces the cost of map distribution, especially maps in color. Will the decreased cost of map distribution increase the use of maps? The problem of map distribution is largely one of economics. Who pays for the making of maps and the costs associated with their distribution?

Mapping is driven by commercial and governmental interests. While business makes decisions on what to map based on what "will sell," the decisions of governments are made based on whose interests will be served. In general, making maps of the country, the world, and other celestial bodies is considered to be in the "national interest." There is also a unique interplay between government and commercial mapping. Maps that are made by governments, often at enormous expense to the taxpayer, are "repackaged" by the private sector and sold as commercial products. The cost of these commercial products has been largely subsidized by the government.

The distribution of maps by the federal government has undergone a huge transformation as a result of computer networks. As late as the mid-1980's, most maps were still distributed on paper. Paper maps were sold on a "cost of distribution" basis - a nominal fee that covered printing, warehousing and associated expenses. Five years later, computer networks had become the prodominant form of map distribution by the federal government. The most remarkable aspect of this transformation is that maps were distributed at no charge. The free distribution of maps was justified because there were no printing and warehousing costs associated with maps distributed through computer networks.

While the maps were now distributed freely, the costs associated with their use had risen sharply. Computers and computer software were needed to make the digital maps usable. While it can be argued that with the appropriate computer software, the digital products were now more useful than the previous paper product, it cannot be overlooked that fewer people were now in the position of using the maps that were so distributed. In a very real sense, the maps that are now distributed by the federal government have become "maps for the few" - usable only to people with computers, computer software, a network connection, and the appropriate training.

There is considerable public interest and support of the World Wide Web, and the Internet in general. Many schools and libraries are establishing connections to the Internet. The number of people that subscribe to services such as America Online and Compuserve has increased drastically and the number of firms that offer Internet access has also expanded. A telling statistic about changing societal attitudes is that in 1995 consumer computer sales in the United States surpassed those of televisions. For better or worse, it seems that our society is becoming "wired" and the form of information access and delivery is drastically changing. Maps, and geographic information in general, will be a part of this change.